Leases (Summary Of Lease Costs) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Amortization of property and equipment	$ 188	$ 608
Interest expense on finance leases	30	93
Total finance lease expense	218	701
Operating lease expense	1,717	4,870
Sublease income	(227)	(679)	$ (910)
Total lease expense	$ 1,708	$ 4,892